scholarly journals Large-Scale Fading and Time Dispersion Parameters of UWB Channel in Underground Mines

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Abdellah Chehri ◽  
Paul Fortier ◽  
Pierre Martin Tardif
Keyword(s):  
Mobile Communications ◽  
Path Loss ◽  
Worker Safety ◽  
Ultra Wideband ◽  
Underground Mines ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
5 Ghz ◽  
Mean Excess Delay ◽  
Uwb Channel

RF channel measurements in underground mines have important applications in the field of mobile communications for improving operational efficiency and worker safety. This paper presents an experimental study of the ultra wideband (UWB) radio channel, based on extensive sounding campaigns covering the underground mine environment. Measurements were carried out in the frequency band of 2–5 GHz. Various communication links were considered including both line-of-sight (LOS) and non-LOS (NLOS) scenarios. In this paper, we are interested in more details of the variations of the RMS delay spread and mean excess delay with Tx/Rx separation, and the variation of RMS with mean excess. The distance dependency of path loss and shadowing fading statistics is also investigated. To give an idea about the behaviour of UWB channel in underground mines, a comparison of our approach with other published works is given including path loss exponent, shadow fading variance, mean excess delay, and RMS delay spread.

scholarly journals Millimeter Wave Propagation Measurements and Characteristics for 5G System

2020 ◽  
Vol 10 (1) ◽  
pp. 335 ◽  
Author(s):  
Ahmed M. Al-Samman ◽  
Marwan Hadri Azmi ◽  
Y. A. Al-Gumaei ◽  
Tawfik Al-Hadhrami ◽  
Tharek Abd. Rahman ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Measurement Data ◽  
Path Loss ◽  
Ultra Wideband ◽  
Line Of Sight ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
5G Systems ◽  
Mean Excess Delay ◽  
Wideband Channel

In future 5G systems, the millimeter wave (mmWave) band will be used to support a large capacity for current mobile broadband. Therefore, the radio access technology (RAT) should be made available for 5G devices to help in distinct situations, for example device-to-device communications (D2D) and multi-hops. This paper presents ultra-wideband channel measurements for millimeter wave bands at 19, 28, and 38 GHz. We used an ultra-wideband channel sounder (1 GHz bandwidth) in an indoor to outdoor (I2O) environment for non-line-of-sight (NLOS) scenarios. In an NLOS environment, there is no direct path (line of sight), and all of the contributed paths are received from different physical objects by refection propagation phenomena. Hence, in this work, a directional horn antenna (high gain) was used at the transmitter, while an omnidirectional antenna was used at the receiver to collect the radio signals from all directions. The path loss and temporal dispersion were examined based on the acquired measurement data—the 5G propagation characteristics. Two different path loss models were used, namely close-in (CI) free space reference distance and alpha-beta-gamma (ABG) models. The time dispersion parameters were provided based on a mean excess delay, a root mean square (RMS) delay spread, and a maximum excess delay. The path loss exponent for this NLOS specific environment was found to be low for all of the proposed frequencies, and the RMS delay spread values were less than 30 ns for all of the measured frequencies, and the average RMS delay spread values were 19.2, 19.3, and 20.3 ns for 19, 28, and 38 GHz frequencies, respectively. Moreover, the mean excess delay values were found also at 26.1, 25.8, and 27.3 ns for 19, 28, and 38 GHz frequencies, respectively. The propagation signal through the NLOS channel at 19, 28, and 38 GHz was strong with a low delay; it is concluded that these bands are reliable for 5G systems in short-range applications.

The 5-GHz Airport Surface Area Channel—Part I: Measurement and Modeling Results for Large Airports

2008 ◽  
Vol 57 (4) ◽  
pp. 2014-2026 ◽  
Author(s):  
David W. Matolak ◽  
Indranil Sen ◽  
Wenhui Xiong
Keyword(s):  
Path Loss ◽  
Correlation Coefficients ◽  
Line Of Sight ◽  
Delay Spread ◽  
Rms Delay Spread ◽  
Amplitude Data ◽  
Amplitude Correlation ◽  
5 Ghz ◽  
Best Fit ◽  
Probability Density Function Pdf

We describe results from a channel measurement and modeling campaign for the airport surface environment in the 5-GHz band. Using a 50-MHz bandwidth test signal, thousands of power delay profiles (PDPs) were obtained and processed to develop empirical tapped-delay line statistical channel models for large airports. A log-distance path loss model was also developed. The large airport surface channel is classified into three propagation regions, and models are presented for each of the regions for two values of bandwidth. Values of the median root-mean-square (RMS) delay spread range from 500 to 1000 ns for these airports, with the 90 th percentile RMS delay spreads being approximately 1.7 ms. Corresponding correlation bandwidths (i.e., correlation value 1/2) range from approximately 1.5 MHz in non-line-of-sight (NLOS) settings to 17.5 MHz in line-of-sight (LOS) settings. Two types of statistical nonstationarity were also observed: 1) multipath component persistence and 2) propagation region transitions. We provide the multipath component probability of occurrence models and describe Markov chains that are used for modeling both phenomena. Channel tap amplitude statistics are also provided, using the flexible Weibull probability density function (pdf). This pdf was found to best fit fading tap amplitude data, particularly for frequently observed severe fading, which is characterized by fade probabilities that are worse than the commonly used Rayleigh model. Fading parameters equivalent to Nakagami-m-model values ofmnear 0.7 were often observed (withm= 1 being Rayleigh and m < 1 being worse than Rayleigh). We also provide channel tap amplitude correlation coefficients, which typically range from 0.1 to 0.4 but occasionally take values greater than 0.7.

scholarly journals Measurements of Building Transmission Loss and Delay Spread at 2.5 GHz

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
L. H. Gonsioroski ◽  
L. da Silva Mello
Keyword(s):  
Transmission Loss ◽  
Signal Transmission ◽  
Delay Spread ◽  
Dispersion Parameters ◽  
Rms Delay Spread ◽  
Urban Buildings ◽  
Time Dispersion ◽  
The Mean ◽  
Mean Excess Delay

This paper presents the results of measurements of signal transmission loss at 2.5 GHz through 10 urban buildings. This allows the characterization of different types of buildings by effective attenuation constants and consideration of the contribution of the transmitted signal in microcell coverage predictions. Power delay profiles (PDPs) of the received signal were also measured and used to determine the time dispersion parameters of the channel, including the mean excess delay and the rms delay spread.

scholarly journals Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Millimeter Wave Bands for 5G Cellular Communications

2018 ◽  
Vol 8 (4) ◽  
pp. 2254 ◽  
Author(s):  
Mohammed B. Majed ◽  
Tharek A. Rahman ◽  
Omar Abdul Aziz
Keyword(s):  
Communication Networks ◽  
Millimeter Wave ◽  
Wide Spectrum ◽  
Path Loss ◽  
Separation Distance ◽  
Propagation Path ◽  
Delay Spread ◽  
Propagation Time ◽  
60 Ghz ◽  
Rms Delay Spread

The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario.

scholarly journals Experimental Characterization of Ultra-Wideband Channel Parameter Measurements in an Underground Mine

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
B. Nkakanou ◽  
G. Y. Delisle ◽  
N. Hakem
Keyword(s):  
Underground Mining ◽  
Path Loss ◽  
Measurement Procedure ◽  
Ultra Wideband ◽  
Small Scale ◽  
Scale Parameters ◽  
Channel Parameter ◽  
Channel Parameters ◽  
Uwb Channel

Experimental results for an ultra-wideband (UWB) channel parameters in an underground mining environment over a frequency range of 3 GHz to 10 GHz are reported. The measurements were taken both in LOS and NLOS cases in two different size mine galleries. In the NLOS case, results were acquired for different corridor obstruction angles. The results were obtained during an extensive measurement campaign in the UWB frequency, and the measurement procedure allows both the large- and small-scale parameters such as the path loss exponent, coherence bandwidth, and so forth, to be quantified. The capacity of the UWB channel as a function of the physical depth of the mine gallery has also been recorded for comparison purposes.

Path loss and delay spread for the stairwell channel at 5 GHz

2015 ◽  
Vol 30 (1) ◽  
pp. e2920 ◽  
Author(s):  
Ruoyu Sun ◽  
David W. Matolak
Keyword(s):  
Path Loss ◽  
Delay Spread ◽  
5 Ghz

scholarly journals Vehicular Channel in Urban Environments at 23 GHz for Flexible Access Common Spectrum Application

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Longhe Wang ◽  
Bo Ai ◽  
Jingya Yang ◽  
Hao Qiu ◽  
Wanqiao Wang ◽  
...  
Keyword(s):  
Mobile Networks ◽  
Dynamic Spectrum Access ◽  
Radio Channel ◽  
Path Loss ◽  
Radio Spectrum ◽  
Urban Environments ◽  
Delay Spread ◽  
Access Technology ◽  
Rms Delay Spread ◽  
New Radio

With the development of the vehicular network, new radio technologies have been in the spotlight for maximizing the utilization of the limited radio spectrum resource while accommodating the increasing amount of services and applications in the wireless mobile networks. New spectrum policies based on dynamic spectrum access technology such as flexible access common spectrum (FACS) have been adopted by the Korea Communications Commission (KCC). 23 GHz bands have been allocated to FACS bands by the KCC, which is expected extensively for vehicular communications. The comprehensive knowledge on the radio channel is essential to effectively support the design, simulation, and development of such radio technologies. In this paper, the characteristics of 23 GHz vehicle-to-infrastructure (V2I) channels are simulated and extracted for the urban environment in Seoul. The path loss, shadow factor, Ricean K-factor, root-mean-square (RMS) delay spread, and angular spreads are characterized from the calibrated ray-tracing simulation results, and it can help researchers have a better understanding of the propagation channel for designing vehicular radio technologies and a communication system in a similar environment.

scholarly journals UWB Radio Propagation Measurements in a Desktop Environment

2010 ◽  
Vol 6 (2) ◽  
pp. 74
Author(s):  
Duje Čoko ◽  
Dinko Begušić ◽  
Zoran Blažević
Keyword(s):  
Radio Propagation ◽  
Ultra Wideband ◽  
Delay Spread ◽  
Personal Area Networks ◽  
Network Analyzer ◽  
Wireless Personal Area Networks ◽  
Impulse Responses ◽  
Rms Delay Spread ◽  
Measurement Results ◽  
Uwb Radio

The ultra-wideband wireless personal area networks are expected to be most commonly employed in desktop environments. This paper presents a measurement campaignconducted on a typical office desk. A pair of omnidirectionalUWB antennas and a vector network analyzer were used tomeasure the impulse responses over a frequency rang spanning from 6 GHz to 8.5 GHz, in accordance with the UWB regulations in Europe. The coherence bandwidth and the rms delay spread are calculated from the measurement results. A significant correlation between these wideband parameters is found, but only at higher correlation thresholds.

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